For many years it has been known that (SN).sub.x may be produced by polymerization of the products of thermal pyrolysis of S.sub.4 N.sub.4 in the presence of hot silver wire. Though it has been suggested that this polymerization occurs spontaneously, a more accurate statement is that the polymerization occurs spontaneously at sufficiently high temperatures, i.e. about 0.degree. C. and above and the rate of polymerization is generally directly proportional to temperature.
It has also been previously reported that (SN).sub.x is a conductive polymer and resembles certain metals in that it exhibits superconductive properties at ultra-low temperatures.
These general properties of (SN).sub.x and a more complete background description of the history of research on (SN).sub.x, the methods of making (SN).sub.x and the characterization thereof may be found in the publications, Preparation and Properties of (SN).sub.x --Street and Greene, IBM Journal Research and Development, March, 1977, pages 99-109 and Electronic Properties of The Superconducting Polymer (SN).sub.x, Greene and Street, CHEMISTRY AND PHYSICS OF ONE-DIMENSIONAL METALS (1977), edited by H. J. Keller and published by Plenum Publishing Corporation, 227 West 17th Street, New York, New York 10011, pages 167-195.
Reference should also be made to Synthesis and Structure of Metallic Polymeric Sulfur Nitride (SN).sub.x, and Its Precursor, Disulfur Dinitride, S.sub.2 N.sub.2, Mikulski, Russo, Saran, MacDiarmid, Garito and Heeger, Journal of the American Chemical Society/97:22/October 29, 1975, pages 6358-6363. Mikulski et al describe precise analytical techniques used to characterize (SN).sub.x polymer and refer specifically to X-ray bombardment for analytical purposes of (SN).sub.x. Similar analysis and techniques, as well as a characterization of S.sub.2 N.sub.2 using X-ray bombardment is described in another publication by many of the same authors, Solid State Polymerization of S.sub.2 N.sub.2 to (SN).sub.x, Journal of the American Chemical Society/98:13/June 23, 1976, pages 3844-3848.
This publication also indicates the presence of free radicals early in the polymerization process and a decrease thereof with time. (Page 3846, Column 1, last paragraph).
Another publication of interest is Raman Scattering and Optical Absorption In S.sub.2 N.sub.2 And Partially Polymerized S.sub.2 N.sub.2 Films--Iqbal and Downs, Solid State Communications, Vol. 20, pages 1147-1150, 1976. In this publication, it is reported that films of S.sub.2 N.sub.2 are polmerized "by raising the temperature" of the material. It is also indicated that in attempted spectral analysis of the S.sub.2 N.sub.2 film, the film "became light blue at the point of incidence of the 632.8 nm laser radiation, probably due to the formation of NS radical or short chain species in S.sub.2 N.sub.2. [Reference is made here to the first above-mentioned Mikulski et al publication. ] The coloration was more intense with the Ar laser lines and therefore complete spectra were recorded only with 632.8 nm radiation." (Page 1148, Column 2 beginning at line 3)
Finally, it should be noted that other publications have indicated the photoinitiated polymerization of other polymer systems, particularly such conventional polymers as polymethyl methacrylate by the use of ultraviolet and gamma irradiation. High-Resolution Polymer Replication of Metallic Patterns--Hiraoka, preprint of paper presented at the 175th Meeting of the American Chemical Society, Division of Organic Coatings and Plastics Chemistry, Anaheim, Calif., Mar. 12-17, 1978.
As a more complete description of the state of background knowledge concerning the present invention, the foregoing publications are incorporated herein by reference.
At a "Conference on Synthesis and Properties of Low-Dimensional Materials" sponsored by the New York Academy of Sciences of June 13-16, 1977, applicants herein, together with other co-authors, presented a paper entitled "(SN).sub.x Grown Under Unusual Conditions" in which the growth of (SN).sub.x crystals from different thermolysis products of S.sub.4 N.sub.4 was described. That paper included an observation that "crystals of S.sub.2 N.sub.2 in tetrahydrofuran are stable in the dark at temperatures below -25.degree.. However, upon irradiation with a weak tungsten source (a microscope illuminator), these transparent crystals attain a dark color within about 30 seconds at temperatures as low as -60.degree., i.e. polymerization is photo-induced." (Emphasis in original).
Still further, applicants herein, together with other co-authors, have published in the Journal of The Chemical Society Chemical Communications, April 5, 1978, a paper entitled "Photopolymerization of S.sub.2 N.sub.2 to (SN).sub.x." Copies of these papers are filed with the present application and the substance thereof is incorporated herein by reference.
Notwithstanding the state of knowledge concerning (SN).sub.x polymers as evidenced by the foregoing, the art has heretofore lacked any means for enhancing initiation of polymerization of (SN).sub.x polymers or for differentially enhancing polymerization so as to produce a conductive pattern of such polymer on a non-conductive substrate. Such product might find use, for example, as an alternative to conventional printed circuit boards.